1. Field
The present disclosure relates to an RFID (Radio Frequency Identification) system using a circular polarized antenna.
2. Background
Many kinds of kiosks including an unmanned search system, an automatic telling machine, an unmanned ticket counter and an automatic vending machine are developed and installed to the benefit of customers.
The kiosks are recently equipped with an RFID system which provides many conveniences such as verifying a customer using the kiosk, and providing a special value-added service to a verified customer. The kiosk equipped with an RFID system is mounted with a reader and a plurality of reader antennas. The customers using the kiosk are respectively issued with tags stored with customer information.
In a case a customer issued with a tag uses a kiosk, the reader reads out the customer information stored in the tag through the reader antenna, where the kiosk verifies the customer using the read-out customer information and provides a special predetermined value-added service to a particular customer.
However, the reader suffers from a disadvantage in that it consumes unnecessary power because it keeps emitting electromagnetic wave through the reader antennas regardless of whether customers have the tags in order to recognize the tags carried by the customers using the kiosk. The reader antennas are conventionally attached on a front side of the kiosk to recognize the tag carried by the customer.
In a case a customer carries a tag in front of a customer body, the reader can easily read out the customer information stored in the tag via the reader antennas.
However, in a case a customer carries a tag in a hip pocket or at a leg instead of a front of a body, the reader cannot correctly recognize the tag, failing to read out the customer information, whereby a special predetermined value-added service cannot be provided to the customer.
In a case the power emitted from the reader antennas is increased, the reader can correctly recognize the tag even if the customer keeps the tag in the hip pocket or at the leg and can provide the customer information stored in the tag.
However, in a case the power emitted from the reader antennas is increased, there may be created a problem of a tag being erroneously operated by recognizing a tag of a customer currently using the kiosk in addition to a tag of a customer waiting in line behind the former customer.